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Beginner lesson How to play Sudoku

Sudoku is logic,
not math.

You never add or calculate. Your job is simply to place the numbers 1 through 9 so none repeats in a row, column, or 3×3 box.

The three rules

  1. Every row must contain 1 through 9 exactly once.
  2. Every column must contain 1 through 9 exactly once.
  3. Every 3×3 box must contain 1 through 9 exactly once.

Where should a beginner start?

Choose a row, column, or box that already contains many numbers. List what is missing, then check the crossing rows and columns. If only one empty square can accept a missing number, that number belongs there.

Good habit

Scan before guessing. A standard Sudoku has a logical path to the solution, so every placement should have a reason.

Your first five moves

  1. Scan each 3×3 box for a number that appears in two neighboring boxes.
  2. Check nearly complete rows and columns.
  3. Identify squares with only one possible number.
  4. Rescan the board after every placement.
  5. Use pencil marks when several possibilities remain.